Stenotrophomonas maltophilia

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Stenotrophomonas maltophilia
Scientific classification
Kingdom: Bacteria
Phylum: Proteobacteria
Class: Gamma Proteobacteria
Order: Xanthomonadales
Family: Xanthomonadaceae
Genus: Stenotrophomonas
Species: S. maltophilia
Binomial name
Stenotrophomonas maltophilia
Palleroni & Bradbury 1993
Synonyms

Pseudomonas maltophilia (ex Hugh and Ryschenkow 1961) Hugh 1981
Xanthomonas maltophilia (Hugh 1981) Swings et al. 1983
Pseudomonas hibiscicola Moniz 1963
Pseudomonas beteli corrig. (Ragunathan 1928) Savulescu 1947

Stenotrophomonas maltophilia is an aerobic, nonfermentative, Gram-negative bacterium which cause uncommon but difficult to treat infections in humans.[1] Initially classified as Pseudomonas maltophilia, S. maltophilia was also grouped in the genus Xanthomonas before eventually becoming the type species of the genus Stenotrophomonas in 1993.[2][3]

S. maltophilia are slightly smaller (0.7-1.8 x 0.4-0.7 μm) than other members of the genus. They are motile due to polar flagella and grow well on MacConkey agar producing pigmented colonies. S. maltophilia are catalase positive, oxidase negative (which distinguishes them from most other members of the genus) and have a positive reaction for extracellular DNase.

S. maltophilia is ubiquitous in aqueous environments, soil and plants, including water, urine, or respiratory secretions; it has also been used in biotechnology applications.[4] In immunocompromised patients, S. maltophilia can lead to nosocomial infections.

[edit] Pathogenesis

S. maltophila frequently colonizes breathing tubes such as endotracheal or tracheostomy tubes, the respiratory tract and indwelling urinary catheters. Infection is usually facilitated by the presence of prosthetic material (plastic or metal), and the most effective treatment is removal of the prosthetic material (usually a central venous catheter or similar device). The growth of S. maltophilia in microbiological cultures of respiratory or urinary specimens is therefore sometimes difficult to interpret and not a proof of infection. If, however, it is grown from sites which would be normally sterile (e.g., blood), then it usually represents true infection.

In immunocompetent individuals, S. maltophila is a relatively unusual cause of pneumonia, urinary tract infection, or blood stream infection; in immunocompromised patients, however, S. maltophilia is a growing source of latent pulmonary infections.[5] S. maltophilia colonization rates in individuals with cystic fibrosis have been increasing.[6]

In UK in 2006 there were about 1000 recorded cases with 300 fatalities (30%).

S. maltophilia is naturally resistant to many broad-spectrum antibiotics (including all carbapenems) and is thus often difficult to eradicate. Many strains of S. maltophilia are sensitive to co-trimoxazole and ticarcillin, though resistance has been increasing.[7] It is not usually sensitive to piperacillin, and sensitivity to ceftazidime is variable.

[edit] References

  1. ^ Gilligan PH, Lum G, VanDamme PAR, Whittier S (2003). Burkholderia, Stenotrophomonas, Ralstonia, Brevundimonas, Comamonas, Delftia, Pandoraea, and Acidivorax. In: Manual of Clinical Microbiology (Murray PR, Baron EJ, Jorgensen JH et al., Eds), 8th ed, ASM Press, Washington, DC, p729–748. ISBN 1555812554. 
  2. ^ Denton M, Kerr K (1998). "Microbiological and clinical aspects of infection associated with Stenotrophomonas maltophilia". Clin Microbiol Rev 11 (1): 57–80. PMID 9457429. 
  3. ^ Palleroni N, Bradbury J (1993). "Stenotrophomonas, a new bacterial genus for Xanthomonas maltophilia (Hugh 1980) Swings et al. 1983". Int J Syst Bacteriol 43 (3): 606–9. PMID 8347518. 
  4. ^ Berg G, Roskot N, Smalla K (1999). "Genotypic and phenotypic relationships between clinical and environmental isolates of Stenotrophomonas maltophilia". J Clin Microbiol 37 (11): 3594–600. PMID 10523559. 
  5. ^ McGowan J (2006). "Resistance in nonfermenting gram-negative bacteria: multidrug resistance to the maximum". Am J Med 119 (6 Suppl 1): S29–36; discussion S62–70. doi:10.1016/j.amjmed.2006.03.014. PMID 16735148. 
  6. ^ Waters V, Gómez M, Soong G, Amin S, Ernst R, Prince A (2007). "Immunostimulatory properties of the emerging pathogen Stenotrophomonas maltophilia (Epub ahead of print)". Infect Immun. doi:10.1128/IAI.01469-06. PMID 17220304. 
  7. ^ Al-Jasser A (2006). "Stenotrophomonas maltophilia resistant to trimethoprim-sulfamethoxazole: an increasing problem". Ann Clin Microbiol Antimicrob 5: 23. doi:10.1186/1476-0711-5-23. PMID 16978420. 

[edit] External links